Apparent depth of a 10m pond with refractive index 4/3

[sphyics]

Any help how to approach this problem.

The depth of pond is 10m. What is the apparent depth for a person looking normally to the water surface? ( Refractive index )water =4/3.

 

[DaveC426913]

Make an attempt.

 

[sphyics]

i solved it by using the forumale (real depth/ apparent depth ) = refractive index

apparent depth comes out to be 7.5m.

My problem is how to get the relation

(real depth/ apparent depth ) = refractive index

 

[Doc Al]

Use Snell's law of refraction and a little trig. (Examine the rays emanating from a point source a distance d under the surface. See how those rays refract. Consider small angles directly above the source.)